Stores reference 6A/839. Supplied to the Air Ministry by S. Smith & Sons (MA) Ltd. London. Metal cased Swiss made Jaeger-Le-Coultre 8-day jewelled lever keyless movement with 7.5cm 24-hour black dial, luminous Arabic numerals and subsidiary 12-hour dial which registers the 'time of trip'. The high quality movement provides a chronograph action for the time of trip. Two knobs located at 4 & 8 o'clock, control the operation of the clock and there will be a lever for regulating the escapement at the back of the case. The left hand knob acts as the winder (anticlockwise turn) and when pulled out can be used to set the time. The knob at 4 o'clock stops the second hand when depressed and a further press re-sets the second hand.
The front of the case lacks paint but is generally good although both knobs are absent and the left spindle is broken at the point where a grub screw would have retained the knob. Fortunately the clock can still be wound using a small flathead screwdriver. Hand adjustment needs to be done using pliers in order to grip and pull out the spindle. The dial and hands are generally in good condition but there is loss of some paint. It is marked with the supplier's details, stores reference code and '39 date. The original glass has is cracked. The clock seems to be in good working order and is currently keeping good time but the 'time of trip' hands do not move. We are unsure if this is controlled by a specific action of one of the knobs/spindles or if it is unserviceable. The clock is snugly mounted into a shaped piece of solid wood and requires effort to remove. We didn't want to mark the wood further so have not checked the rear of the casing for marks but would expect to find Air Ministry details engraved into the back. We believe the MK.IIIB that was fitted to early Hurricane & Spitfire fighters as well as some Beauforts, Battles, Beaufighters & other aircraft. The 24 hour version (IIIB) is considerably rarer than the 12 hour (IIIA). Stock code C24488.